Polymeric fibers and microporous films by photo‐crosslinking of triphenylene‐derived liquid crystals. Issue 5 (18th December 2018)

• Record Type: Journal Article
• Authors: Hirose, Takuji; Xu, Zhe; Kikuchi, Yuka; Fukushima, Masahito; Kawamura, Kengo; Kaguchi, Yosuke; Kodama, Koichi; Yasutake, Mikio
• Is Part Of: Journal of polymer science. Volume 57:Issue 5(2019)
• Page Start: 605
• Page End: 612
• Publication Date: 2018-12-18
• Subjects: cinnamate -- fiber -- microporous film -- memebranes -- photo‐crosslinking -- photopolymerization -- self‐assembly -- structure‐property relations -- triphenylene‐derived liquid crystals; 547
• DOI: 10.1002/pola.29299
• Languages: English
• ISSNs: 0887-624X

Abstract

ABSTRACT: Two series of photoreactive discotic liquid crystals consisting of a triphenylene core and six cinnamate units with one (TPC1 n ) or two (TPC2 n ) n ‐alkoxy groups (C n H2 n +1 O; n = 10–14), respectively, as peripheral groups are synthesized. Both of them are polymerized into fibers up to 2 mm long by UV irradiation in liquid paraffin in the columnar LC temperature ranges. The fiber structures seem to be preconstructed in liquid paraffin. In addition, TPC2 n are shown to form microporous films up to 15 μm in diameter by simply casting the solutions of some solvents followed by drying for several minutes in air at room temperature. Photoirradiation of the films in the LC temperature range converts them to polymeric ones while preserving the microporous and hexagonally ordered structure. From comparison withTPC1 n and the hydrogenated derivative ofTPC2 12, the porous film‐forming property is suggested to result from the combination of the double bond of the cinnamoyl group and the two long alkoxy chains on the phenyl ring. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2019, 57, 605–612 Abstract : Triphenylene‐derived liquid crystals (TPC1 n andTPC2 n [ n = 12–14]) are shown to self‐assemble to fibers in liquid paraffin at the columnar liquid crystalline temperature range and also to form microporous films forTPC2 n by casting its solutions at room temperature. They can be crosslinked to polymers, preserving their morphology, fibers, and films, by the [2 + 2] photocyclization of cinnamate units in the periphery by UV irradiation in the columnar liquid crystalline states.